This invention relates to auxiliary or storm windows and more particularly to a window which can be inexpensively installed on the inside of the window frame.
Escape of heated air through broken window panes, and cracks around panes and by conduction through single pane windows is a severe problem, particularly in older houses. Weatherizing these windows is particularly difficult because until the late 1940's there was no standardization of window size. Windows in older houses are wide and low, narrow and high. Some operate up and down, some left or right, some open out and some open in. To aggravate the problem still further, it has been estimated that approximately 75% of the windows in these older houses are out of square.
A long-life, efficient, flexible and reasonably priced window is required for installation on these older homes. The prior art window weatherization techniques have not been completely satisfactory. Clear plastic film has been used because it is inexpensive and easy to install. This film has a very short life, low efficiency, poor appearance and the window cannot thereafter be operated without destroying the film. Plastic panels also have been permanently installed on windows. These have the advantage of inexpensive installation and provide good efficiency. However, they cannot be operated. Also, there is a high waste factor in installation because a full plastic sheet must normally be used in weatherizing one window.
Glass storm windows have been in use for a number of years. They are very expensive, dangerous, provide only average efficiency and present installation problems, particularly where they must be custom made to fit odd shaped windows. One such storm window is illustrated in U.S. Pat. No. 2,745,485 to Etling. Etling discloses a storm window which may be adapted to window casings of various dimensions, however these storm windows are placed within rather than over the window casing, thus requiring the installer to fit the window to rather precise dimensions.